聚丙烯纤维气泡混合轻质土抗压力学性能研究

通过聚丙烯纤维气泡混合轻质土标准试件无侧限抗压试验来探究聚丙烯纤维含量及纤维长度对气泡混合轻质土抗压强度的影响。试验结果表明:气泡混合轻质土的抗压强度随着聚丙烯纤维含量的增加而提高,且龄期越长,其强度增长效果越显著;当抗压强度达到峰值后,随着聚丙烯纤维长度的增加,气泡混合轻质土的抗压强度曲线呈降低趋势,且存在纤维长度最优值。结合材料应力-应变曲线,采用坐标无量纲化处理及分段式受压曲线方程理论,初步建立了聚丙烯纤维气泡混合轻质土单轴受压全曲线函数方程,并采用离散数据数值分析方法对应力-应变曲线下降段的理论函数方程进行修正,给出了具有明确物理意义的聚丙烯纤维气泡混合轻质土单轴受压全曲线分段函数方程。

Study on the Uniaxial Compressive Mechanical Properties of Foamed Mixture Lightweight Soil with Polypropylene Fibers

The effect of polypropylene fiber content and length on the compressive strength of foamed mixture lightweight soil was investigated through unconfined uniaxial compressive strength tests. The test results show that the compressive strength of foamed mixture lightweight soil increases with the increase of polypropylene fiber content, and longer age brings the more obvious reinforcing effect. As the compressive strength reached the peak value, the compressive strength curve of foamed mixture lightweight soil decreased with the increase of polypropylene fiber length, and the optimum value of fiber length exists. Based on the uniaxial compressive stress-strain curve of the material, the full curve function of the uniaxial compression for the polypropylene fiber foamed lightweight mixture soil was preliminarily established by using the dimensionless processing and the theory of segmented pressure curve equation. The theoretical function equation for the falling section of the stress-strain curve was modified by the numerical analysis method of discrete data. The piecewise function equation of the uniaxial compression for the polypropylene fiber foamed mixture lightweight soil is defined.